1. Field of the Invention
The present invention relates in general to glareshields for use in vehicles, particularly in fixed and rotor wing aircraft. More particularly, in particular to glareshields that enhance safety during aircraft crashes.
2. Description of the Prior Art
While significant progress has been made to increase the safety of fixed wing and rotor wing aircraft, a significant number of crashes still occur. However, the survivability of aircraft crashes has increased with incremental advances in the engineering of the aircraft and of the aircraft components. Head injuries, in particular, must be avoided in order to further increase the overall survivability.
This has been demonstrated in automobile safety advances, such as the implementation of air bag safety equipment, which protect the head and upper body of the driver and passenger in the front seats. A comparable situation arises in aircraft. The pilot and copilot are restrained by safety belts and safety harnesses. In longitudinal crashes, the restrained crew member experiences significant forward head motion which sometimes causes the head to strike the glareshield and/or instrument panel. This can cause severe injury or death in a crash which would have been otherwise survivable.
The present invention is directed to an improved glareshield for use in vehicles, particularly in fixed wing and rotary wing aircraft, or in combination or hybrid aircraft, such as an aircraft with tilting rotor assemblies which allow both a fixed wing mode of flight and a rotor wing mode of flight, i.e., a tiltrotor aircraft.
More particularly, the present invention is directed to an improved glareshield which includes multiple portions of varying strength which allow the glareshield to fold or collapse in a controlled manner when it is struck by the head or helmet of a crew member during a crash, thus reducing the deceleration force experienced by the head, and thereby enhancing safety and increasing survivability.
Still more particularly, the present invention is directed to an improved glareshield which includes an array of high strength segments oriented within the glareshield in a predetermined pattern which defines a plurality of portions of the glareshield which, in effect, act as xe2x80x9chingesxe2x80x9d to allow the controlled folding or collapsing of the glareshield when struck. This folding process absorbs kinetic energy from the occupant""s head and helmet at controlled levels below the injury threshold.
During impact, the improved glareshield of the present invention folds down over the instrument panel, which is underneath it, allowing the energy-absorbing padded top surface of the glareshield to protect the head from a high force impact with the hard portion of the instrument panel.
In accordance with the preferred embodiment of the present invention, the glareshield includes a layer of foam pad which has a nonlinear stiffness and a low coefficient of restitution to maximize the amount of energy absorbed by the head.
The improved glareshield of the present invention functions somewhat like a pre-deployed air bag to protect the from head injury during a crash. However, it is entirely a passive device, which does not need to be instantaneously deployed at the moment of impact. It is a relatively low-cost and fail-safe means for reducing head injury that requires no moving parts and no deployment mechanisms.
The above as well as additional objectives, features, and advantages will become apparent in the following description.